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Serghei Berezovschi
13,360 PointsHow does Object obj get passed into compareTo method?
I doesn't look like this method gets called in any of the classes.
1 Answer
Alexander Nikiforov
Java Web Development Techdegree Graduate 22,175 PointsCould you be more specific what exactly you don't understand?
How does Object obj get passed into compareTo method?
Object obj is passed as argument:
compareTo(Object obj) ... ?
About this:
I doesn't look like this method gets called in any of the classes.
It gets called behind the scenes, when you write sort on the Array containing Treets. If the array contains objects that implement Comparable and @Override compareTo, sort function uses that to sort Array...
Read docs description of sort method:
https://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html#sort(java.lang.Object[])
Quote from it:
Sorts the specified array of objects into ascending order, according to the natural ordering of its elements. All elements in the array must implement the Comparable interface. Furthermore, all elements in the array must be mutually comparable (that is, e1.compareTo(e2) must not throw a ClassCastException for any elements e1 and e2 in the array).
Does it make sense ?
tomtrnka
9,780 Pointstomtrnka
9,780 PointsFinally, great answer. I was wandering what is the connection between Arrays.sort() and compareTo() . Why do we implement Comparable interface. It wasnt that clear from the video :)